CAT commands (“Card Application Toolkit” commands) are a collection of commands that extend the functionality of portable data carriers, in particular of (U)SIM mobile communication cards. The CAT commands are defined by ETSI, the European Telecommunications Standards Institute, in the specification TS102 223. These are commands of the (U)SIM mobile communication card to the telecommunication terminal, with which commands the telecommunication terminal and its components, e.g. the display, the keyboard and the like, can be directly addressed or queried. CAT commands furthermore also enable the sending of messages, e.g. SMS messages, or the setup of a voice connection through the (U)SIM mobile communication card. Such commands are also referred to as proactive commands, because they can be independently executed by the (U)SIM mobile communication card.
For executing a proactive command it is therefore necessary to reverse the conventional master/slave relationship between the telecommunication terminal and the (U)SIM mobile communication card. For commands of the “SIM Application Toolkit” implemented on usual (U)SIM mobile communication cards, said commands constituting a subset of those of the “Card Application Toolkit”, the telecommunication terminal sends for example at regular intervals a request to the (U)SIM mobile communication card as to whether a SIM Application Toolkit command is present for processing. This procedure is referred to as “polling”.
Modern (U)SIM mobile communication cards often have a web server application (“SCWS”, Smart Card Web Server). The latter is adapted to provide to a web browser of the telecommunication terminal, on request, contents which are stored in the mobile communication card in the form of HTML documents. In this manner it is possible to present applications which are implemented completely on the mobile communication card, such as a phone book application, to a user of the telecommunication terminal in the form of HTML pages in the easy-to-use manner familiar to him from the Internet. Furthermore, the corresponding application can be easily transferred together with the mobile communication card to another telecommunication terminal as long as a web browser is available there.
Such applications, such as the above-mentioned phone book application, which partly make use of CAT commands must therefore support a mechanism which activates corresponding CAT commands on the mobile communication card when e.g. on the basis of an action of the user of the telecommunication terminal, for example the selection of a number from the phone book represented as an HTML document by clicking on said number, the corresponding CAT command for setting up a connection with the stated number is to be executed.
WO 2006/085201 A1 solves this problem by the phone book entry comprising a reference to a Java servlet stored on the mobile communication card and executable on a processor of the mobile communication card, wherein a click on the entry activates the servlet, which in its turn triggers the execution of the corresponding CAT command for dialing the number belonging to the phone book entry.
In WO 2007/105084 A1 there is described an application implemented as an applet, which makes SIM Toolkit commands and their interdependence displayable to a user of a telecommunication terminal. The application translates for this purpose the individual SIM Toolkit commands into corresponding HTML pages. The latter are displayed to the user and can be scrolled in accordance with the interdependencies of the SIM Toolkit commands by means of the navigation known from HTML pages. The statement of which of the commands displayed as described hereinabove is to be called is sent through an HTTP request to the application, which initiates an execution of the corresponding command.
For supporting an interaction between a web server application which makes available HTML contents on the (U)SIM mobile communication card, and a CAT interpreter for executing CAT commands on the (U)SIM mobile communication card, the prior art thus always makes use of an application usually implemented on the basis of the programming language Java. This requires a corresponding Java runtime environment on the (U)SIM mobile communication card, which makes substantial resource demands on the (U)SIM mobile communication card, and generally slows down the execution of the corresponding CAT commands.